Features of Icebreaker Women's Multisport Light Micro Sock Achilles support keeps your sock in place Instep support for stability Seamless toe closure to reduce bulk and prevent blisters Breathe zone for improved ventilation Function junction to eliminate bulk Fabric Details Merino Wool 59%, Nylon 39%, Lycra 2% Fibre micron: Merino Wool 21.5 micron